Research On Resource Allocation And Precoding In Multicell OFDMA Network

As the development of next-generation wireless broadband cellular networks,base station (BS) cooperation has become a promising tool to increase the per-cellspectral efficiency as well as cell-edge user throughput. Existing BS cooperation tech-niques can be mainly characterized into two classes. One is coordinated scheduling,which solves the problem from the resource allocation aspect, and the other is coordi-nated beamforming or joint processing, which is from the pre-coding aspect.In the resource allocation part, we propose a user-based adaptive joint channelassignment scheme. In the proposed scheme, all the cell-edge users from multiplecells are scheduled jointly while cell-centre users are scheduled in each individualcell. The method exploits both multi-user diversity and frequency diversity. It avoidsthe dominant inter-cell interference via the so-called Assignment Table. To apply thealgorithm in a large coordination set, a cell grouping method together with a groupcoordination method is also introduced. Simulation results show that the proposedscheme can increase considerably the average cell throughput compared with existinginter-cell interference coordination schemes. In the second part we introduce a newmulti-cell cooperation model, where each cooperating BS simultaneously serves twoco-channel users, one from the cell edge and the other from the cell center. It differsfrom the conventional base station cooperation system, i.e., multi-cell MU-MIMO,where the MU-MIMO model is only adopted for the users belong to the coopera-tion set. Four distributed coordinated beamforming (including center user scheduling)schemes for the considered multi-cell MU-MIMO with respective user paring schemesare proposed. Simulation results show that the SLNR based scheme and the ZF-SLRNscheme are able to considerably improve both the system total throughput and edgeuser throughput. Base station cooperation is an emerging technique which has a promising futuredue to its inherent ability to mitigate the interference and thus to improve the perfor-mance of the overall system. We believe that Coordinated Multipoint Transmissionwill play an important role in the next generation wireless communication.